title: Differential proteomic analysis of platelets suggested possible signal cascades network in platelets treated with salvianolic acid B.
abstract: BACKGROUND
  Salvianolic acid B (SB) is an active component isolated from Danshen, a traditional Chinese medicine widely used for the treatment of cardiovascular disorders. Previous study suggested that SB might inhibit adhesion as well as aggregation of platelets by a mechanism involving the integrin α2β1. But, the signal cascades in platelets after SB binding are still not clear.
  
  
  RESULTS
  In the present study, a differential proteomic analysis (two-dimensional electrophoresis) was conducted to check the protein expression profiles of rat platelets with or without treatment of SB. Proteins altered in level after SB exposure were identified by MALDI-TOF MS/MS. Treatment of SB caused regulation of 20 proteins such as heat shock-related 70 kDa protein 2 (hsp70), LIM domain protein CLP-36, copine I, peroxiredoxin-2, coronin-1 B and cytoplasmic dynein intermediate chain 2C. The regulation of SB on protein levels was confirmed by Western blotting. The signal cascades network induced by SB after its binding with integrin α2β1 was predicted. To certify the predicted network, binding affinity of SB to integrin α2β1 was checked in vitro and ex vivo in platelets. Furthermore, the effects of SB on protein levels of hsp70, coronin-1B and intracellular levels of Ca²+ and reactive oxygen species (ROS) were checked with or without pre-treatment of platelets using antibody against integrin α2β1. Electron microscopy study confirmed that SB affected cytoskeleton structure of platelets.
  
  
  CONCLUSIONS
  Integrin α2β1 might be one of the direct target proteins of SB in platelets. The signal cascades network of SB after binding with integrin α2β1 might include regulation of intracellular Ca²+ level, cytoskeleton-related proteins such as coronin-1B and cytoskeleton structure of platelets.
authors.affiliation: Shanghai Research Center for Modernization of Traditional Chinese Medicine, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, People's Republic of China.
authors.forename: Chao
authors.initials: C
authors.lastname: Ma
authors.forename: Yan
authors.initials: Y
authors.lastname: Yao
authors.forename: Qing-Xi
authors.initials: QX
authors.lastname: Yue
authors.forename: Xin-Wen
authors.initials: XW
authors.lastname: Zhou
authors.forename: Peng-Yuan
authors.initials: PY
authors.lastname: Yang
authors.forename: Wan-Ying
authors.initials: WY
authors.lastname: Wu
authors.forename: Shu-Hong
authors.initials: SH
authors.lastname: Guan
authors.forename: Bao-Hong
authors.initials: BH
authors.lastname: Jiang
authors.forename: Min
authors.initials: M
authors.lastname: Yang
authors.forename: Xuan
authors.initials: X
authors.lastname: Liu
authors.forename: De-An
authors.initials: DA
authors.lastname: Guo
mesh_terms: D000818:Animals; D001572:Benzofurans / Q000378:metabolism / Q000494:pharmacology*; D001792:Blood Platelets / Q000737:chemistry / Q000187:drug effects* / Q000378:metabolism*; D038982:Integrin alpha2beta1 / Q000378:metabolism; D008297:Male; D053858:Metabolic Networks and Pathways / Q000187:drug effects*; D008954:Models, Biological; D010973:Platelet Adhesiveness / Q000187:drug effects; D010974:Platelet Aggregation / Q000187:drug effects; D011506:Proteins / Q000032:analysis / Q000378:metabolism; D020543:Proteome / Q000032:analysis / Q000187:drug effects*; D040901:Proteomics / Q000379:methods; D051381:Rats; D017207:Rats, Sprague-Dawley; D053630:Depsides
chemical_list: D001572:Benzofurans; D038982:Integrin alpha2beta1; D011506:Proteins; D020543:Proteome; C076944:salvianolic acid B; D053630:Depsides